Protecting media items using a media security controller

ABSTRACT

A media storage device includes a media security controller circuit and a memory to store data that relates to a media item to be rendered by a rendering device. The media security controller circuit sends a message to the rendering device that causes the rendering device to obtain a portion of data from memory of the media storage device and provide it to the media security controller circuit. The portion is received and transformed by the media security controller circuit. The media security controller circuit sends the transformed portion to the rendering device.

RELATED APPLICATIONS

This application is a continuation of Ser. No. 14/415,568, filed Jan.16, 2015, which is a National Stage entry of PCT Application No.PCT/US2013/050947, filed Jul. 15, 2013, which claims the benefit of U.S.Provisional Application No. 61/673,023, filed Jul. 18, 2012 and U.S.Provisional Application No. 61/683,679, filed Aug. 15, 2012, each ofwhich is incorporated by reference herein.

TECHNICAL FIELD

The present disclosure relates to protecting media items and, moreparticularly, to a technique of protecting media items using a mediasecurity controller (MSC).

BACKGROUND

As downloading of content (e.g., movies, music, books, images,documents, etc.) in digital format becomes increasingly common as amethod of content distribution, the issue of securing the content toprevent and/or to identify piracy has become of great concern to contentproducers (e.g., movie studios, record labels, book publishers, etc.).Traditional media storage devices may include a media securitycontroller to ensure that a host device (e.g., media player) can accessa media file in a public partition on the media storage device.Generally, media security controllers lack the capability to implementsecurity features for limiting the rendering of a media item.Conventionally, authorization keys and security are managed by the hostdevice. The host device typically stores the authorization keys toenable decryption and playback of the media file(s). Traditionalsolutions offer limited security in that if the host device iscompromised (e.g., hacked) the authorization keys may be used by otherdevices, and such attacks are not limited or blocked by media.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will be understood more fully from the detaileddescription given below and from the accompanying drawings of variousimplementations of the disclosure.

FIG. 1 illustrates example system architecture, in accordance with oneor more implementations.

FIG. 2 illustrates an example media storage device, in accordance withone or more implementations.

FIG. 3 illustrates example instructions in an authorization file forprotecting a media item using a media security controller, according tovarious implementations.

FIG. 4 is a diagram of an example of communications between a mediastorage device and rendering device for protecting a media item,according to various implementations.

FIG. 5 is a diagram of an example of communications between a mediastorage device and rendering device for protecting a media item,according to various implementations.

FIG. 6 illustrates example key management instructions for protecting amedia item using a media security controller, according to variousimplementations.

FIG. 7 is a block diagram of an example computer system that may performone or more of the operations of a media security controller describedherein, in accordance with various implementations.

FIG. 8 is a block diagram of an example computer system that may performone or more of the operations of a security module described herein, inaccordance with various implementations.

DETAILED DESCRIPTION

A system and method for protecting media items involving a mediasecurity controller (MSC) is described, according to variousimplementations. A rendering device may obtain media data from the mediastorage device, but may not be independently able to interpret the mediadata. In order to understand the media data, the rendering device canforward the media data to a MSC, and the MSC can transform (e.g.,decrypt, encrypt, compress, etc.) the media data to allow the renderingdevice to interpret the media data. In this way, a rendering device'sability to render a media file depends on its interactions with the MSC.Unlike conventional media controllers, MSC implementations add securityintelligence to media devices, and the MSC acts as an intermediarybetween a rendering device and a media file to be rendered. Also unliketraditional media controllers, MSC implementations can internally storeand manage authorization keys for media items including those stored onthe media itself. For example, the MSC can provide the rendering devicewith information (e.g., obtained by using an authorization key in asecurity operation) that the rendering device should use to render themedia file. In another example, the MSC can decrypt a portion of themedia file for the rendering device and can provide the decryptedportion to the rendering device (e.g., to be played directly, combinedwith other data, further decrypted, etc.). Systems using MSCs allowcontent providers (e.g., media publishers, distributors) to ensure a MSCis involved in the rendering process. For example, a publisher mayconfigure the licensing of a media item such that a portion of the mediaitem or one of the media data decryption keys are decrypted by the MSC.

Examples of a media item can include, and are not limited to, digitalmovies, digital video, digital photos, digital music, website content,social media updates, electronic books (ebooks), electronic magazines,digital newspapers, digital audio books, electronic journals, web blogs,real simple syndication (RSS) feeds, electronic comic books, softwareapplications, etc.

A media item can be consumed via the Internet or other networks (such asby streaming the media item from a media device to a remote device)and/or more directly via an application or locally-connected device. Forbrevity and simplicity, a digital movie (also hereinafter referred to asa movie) is used as an example of a media item throughout this document.As used herein, “digital content,” “media,” media item,” “online mediaitem,” “digital media,” and a “digital media item” can include anelectronic file that can be played, executed or loaded using software,firmware, and/or hardware configured to present the media item to auser.

FIG. 1 illustrates example system architecture 100, in accordance withvarious implementations. The system architecture 100 can include one ormore servers 110,115 associated with one or more content providers103,105 (e.g., media item publishers), one or more key issuance servers120, one or more media storage devices 130,131, and one or morerendering devices 160 coupled via one or more networks 150.

The one or more networks 150 can include one or more public networks(e.g., the Internet), one or more private networks (e.g., a local areanetwork (LAN) or one or more wide area networks (WAN)), one or morewired networks (e.g., Ethernet network), one or more wireless networks(e.g., an 802.11 network or a Wi-Fi network), one or more cellularnetworks (e.g., a Long Term Evolution (LTE) network), routers, hubs,switches, server computers, and/or a combination thereof.

The rendering devices 160 can include devices to render media items, andmay be (but are not limited to) portable media players, netbooks, laptopcomputers, electronic book readers, tablet computers, desktop computers,set-top boxes, gaming consoles, televisions, cellular telephones,personal digital assistants (PDAs), and the like. The rendering device160 functionality may be implemented in hardware or software, or acombination thereof. The rendering device 160 can also be implemented ina component, such as a graphics card/accelerator, media interface, orconditional access device. The rendering device 160 may be controlled bya remote control, a touch screen, a keyboard, a mouse, gesture input, orany other input device. The rendering device 160 may have Internet (orother network) connectivity and the connectivity may be sporadic. (Forexample, network connectivity may be required to download content orauthorize transfers of content between devices, but may not be requiredduring playback so as to permit playback in offline or low-bandwidthenvironments). The rendering device 160 can internally containcryptographic keys and security logic, as well as the ability tointerface with media and output video to the user. The rendering device160 can include video decompression support (e.g., an MPEG2, H.264and/or HEVC codec), as well as the ability for the user to select andmanage various video streams (e.g., a menuing system, which can berudimentary such as the system employed in the DVD format or moresophisticated and/or programmable capabilities such as BD-J employed onBlu-ray).

The individual rendering devices 160 can include a media viewer 163. Inone implementation, the media viewers 163 are applications that allowusers to view media items, such as movies, etc. For example, the mediaviewer 163 may include video decoding capabilities (e.g., codecs forMPEG-2, MPEG-4/H.264, VC-1, or other compression standards), and audiodecoding capabilities. Media viewer 163 may, in some implementations,include user interface elements so the user can select or interact withcontent to play, and may include a web browser that can access,retrieve, present, and/or navigate content (e.g., web pages such asHyper Text Markup Language (HTML) pages, digital media items, etc.)contained on media storage device 131 or from other sources (e.g., webservers).

The media viewer 163 can render, display, and/or present the content(e.g., a web page, a media viewer) to a user. The media viewer 163 maybe an embedded media player (e.g., a Adobe Flash player or an HTML5player) that is embedded in a document (e.g., a web page). The mediaviewer 163 may also include dedicated hardware elements, such asdedicated decoders implemented in silicon, e.g. as part of a larger SoC(System on Chip) and/or as standalone chip(s). In another example, themedia viewer 163 may be a standalone application or a capability of astandalone application (e.g., a mobile application, desktop application,gaming console application, television application, etc.) that allowsusers to view digital media items (e.g., movies). The media viewer 163can be provided to the rendering devices 160 by a server and/or contentdistribution platform. For example, in some embodiments, a media viewer163 may be an embedded media player that is embedded in a document(e.g., web pages) or movie file provided by the content distributionplatform. In another example, the media viewers 163 may be separateapplications that are downloaded from a server. In another example, themedia viewers 163 may be standalone applications that are pre-installedon the rendering devices 160. The media viewer may be stored on mediastorage devices 130,131, or may be stored elsewhere.

The servers 110,115,120 can include one or more computing devices (suchas a rackmount server, a router computer, a server computer, a personalcomputer, a mainframe computer, a laptop computer, a tablet computer, adesktop computer, etc.), data stores (e.g., hard disks, SSDs,network-attached storage devices, memories, databases), networks,software components (operating systems, middleware, applicationsoftware, databases, etc.), hardware security modules (e.g. PC cards,smart cards, USB security peripherals), and/or other components that maybe used to provide a user with access to media items and/or provide themedia items to the user.

The media storage device 130 can include at least one MSC 135 (such as asecure CPU (central processing unit) with internal ROM, keys, keystorage, etc.) as well as storage 140 (such as flash memory or harddrives). A CPU is an example of a processing device. The MSC 135 can bea separate chip, or can be integrated with other functionality (such asa USB, flash, or hard disk controller). The bulk storage 140 can beimplemented on separate hardware within the media from the MSC 135, orthey could be integrated (e.g., as a single chip). Examples of physicalform factors for the media storage device 130 include without limitationflash memory cards, USB sticks, hard disks, SSDs, network attachedstorage devices, etc. It should be noted that, depending on theembodiment, the MSC may or may not be aware of how data is organized onstorage 140. If the MSC 135 lacks such awareness (as may be the case ifthe media storage device 130 is a block storage device using a filesystem that is not known to MSC 135), then the process involved for theMSC 135 to obtain data contained on storage 140 may include having theMSC 135 provide a message to the player (or host or rendering device) toread data from bulk storage, possibly decrypt the data, and send thedata back to the media device. The storage 140 can store media items anddata pertaining to the media items. The storage 140 can include one ormore data stores that can be memory (e.g., random access memory), cache,drives (e.g., hard drive), flash drives, one-time programmable storage,or another type of component or device capable of storing data. The datastored on storage 140 is not limited to media files that utilize thesecurity capabilities of MSC 135 (e.g., storage 140 can operate as anormal hard drive or flash drive, with standard file systems, and canhold any kind of data including both legacy files and files using MSC135 for playback).

The MSC 135 can be part of or coupled (or otherwise directly orindirectly connected) to the rendering device 160. The MSC 135 can addsecurity features to protect the media items that are stored in thestorage 140. The MSC 135 can act as an intermediary component betweenthe rendering device 160 and the movie in the storage 140 to berendered, and can include functionality to assist in securing orenabling such rendering. For example, the rendering device 160 cannotrender Action-Movie-XYZ in media viewer 163 without the MSC 135processing some of the data needed to render Action-Movie-XYZ in mediaviewer 163. For example, the MSC 135 can decrypt one or more keys thatshould be used for rendering the media item and provide the keys to therendering device 160, and/or decrypt precursors to actual decryptionkeys, and/or decrypt a portion of the media item and provide thedecrypted portion to the rendering device 160. The interaction betweenthe MSC 135 and the rendering device 160 can be iterative. The number ofiterations can be based on instructions that relate to (and may bestored with) the media item.

The rendering device 160 can access the data (e.g., media items, datapertaining to the media items) in the storage 140. The data in thestorage can be secured (e.g., encrypted) to prevent the rendering device160 from rendering (whether by the stored data in the media viewer 163or rendering by unauthorized devices) without use of the requiredsecurity procedures. As noted previously, the rendering device 160 caninclude a security module 165 which can, directly or indirectly,exchange data with the MSC 135 to enable the processing and exchange ofdata to allow rendering in the media viewer 163.

In one implementation, the MSC 135 does not have the ability to directlyread from files contained on storage 140. For example, MSC 135 may notunderstand the file system utilized by the rendering device 160. If theMSC 135 requires data from storage 140, the MSC 135 can send a messageto rendering device 160 specifying the desired data, then renderingdevice 160 can obtain data from storage 140 and to provide the data backto the MSC 135. The MSC 135 can then, for example, utilize the data(e.g. as part of its own operation) or it may process the data and cansend the processed data to the security module 165 (e.g. directly or byway of rendering device 160). The security module 165 can use the datafrom the MSC 135 to render the media item (e.g., movie) in the mediaviewer 163.

The rendering device 160 can be coupled to the media storage device 130to access the media item (e.g., movie) in the storage 140 to render themedia item in the media viewer 163. The rendering device 160 can includea security module 165, which can communicate (directly or indirectly)with the MSC 135. The security module 165 can be for example, and is notlimited to, firmware, an application, a security core on a SoC, aseparate chip, and/or other hardware in the rendering device 160. When auser 102 selects a movie to render in the media viewer 163, the securitymodule 165 can load an authorization file for the movie from the storage140. The authorization file can include one or more sets of instructionsfor the security module 165 and for the MSC 135 to execute in order torender the movie on the media viewer 163. The security module 165 canreceive and interpret instructions from the MSC 135 and/or from theauthorization file. Likewise, the MSC 135 can receive and interpretinstructions from the security module 165 and/or from the authorizationfile.

The key issuance server 120 can distribute and manage keys for therendering devices 160 and media storage devices 130,131. The keyissuance server 120 can issue one or more base media storage device keysfor the media storage devices 130,131. For example, when the mediastorage devices 130,131 are manufactured, the key issuance server 120can supply (143) one or more base media storage device keys in thesecure memory portion (e.g., in an on-chip one-time-programmable memory)of the MSC 135 of the media storage device 130,131. The base mediastorage device keys can be unique for each media storage device 130,131.Examples of a base media device key can include, and are not limited to,an asymmetric key pair (e.g., RSA/ECC), a symmetric key (AES keys), etc.The base media storage device keys can be used to establish a securesession with an authorization server 110, a rendering device 160, etc.The process of supplying a key can, for example, include having keyissuance server 120 directly transmit the key in a secure facility, orkeys can be delivered to a key programming device in a secure facilitywhich then provides the key to individual devices, and/or the key can besent in secured (e.g., encrypted) form over an untrusted channel such asthe Internet.

The key issuance server 120 can issue one or more rendering device keysfor the rendering devices 160. For example, when a rendering device 160is manufactured, the key issuance server 120 can supply (149) one ormore rendering device keys to the rendering device 160. The process ofsupplying a key can, for example, include having key issuance server 120directly transmit the key in a secure facility, or keys can be deliveredto a key programming device in a secure facility which then provides thekey to individual devices, and/or the key can be sent in secured (e.g.,encrypted) form over an untrusted channel such as the Internet.

The content provider 105 can include one or more media servers 115 toprovide media items, for example, for a rendering device 160 to renderfor a user 102. The content provider 105 can include one or moreauthorizations servers 110 to provide authorization files for the mediaitems to allow the media items to be rendered.

The authorization servers 110 can provision the authorization keys intoMSCs 135. For example, when a movie is purchased (e.g. by user 102), themedia server 115 can supply (145) a data file for the purchased moviethat will be stored on the media storage device (e.g.,Media-Storage-Device-n 131), and the authorization server 110 can send(147) an authorization file and an authorization key for the movie forstorage on the media storage device. For example, when the movie ispurchased, the data file, the authorization file, and the authorizationkey for the movie can be downloaded from the authorization server 110and from the media server 115 to the storage 140 on theMedia-Storage-Device-n 131. The authorization key can be stored in theMSC 135 (or encrypted with a key stored in the MSC 135 and storedelsewhere on storage 140), and the data file and the authorization filecan be stored in storage 140. One implementation of storing theauthorization keys in the MSC 135 is described in greater detail belowin conjunction with FIG. 2.

The key issuance server 120 can provide data to authorization server 110for use in preparing and/or encrypting authorization keys. In oneimplementation, the key issuance server 120 provides (141) toauthorization server (110) a list of derived keys that are based on thebase media storage device keys it supplies (143) to media storagedevices (131). The derived keys can be used by authorization server 110to securely transfer information (such as authorization keys) for use byMSCs 135. One implementation uses a key tree to produce the derived keysis described in greater detail below in conjunction with FIG. 6.

The authorization file can include sets of instructions and data forexecution by the security module 165 on the rendering device 160 and theMSC 135 on the media storage device. For example, an exemplaryauthorization file's instructions can instruct the security module 165to retrieve data that is encrypted from the storage 140 for the movieand to provide the encrypted data to the MSC 135. The exemplaryauthorization file can also include instructions for the MSC 135 todecrypt the encrypted data using the authorization key that is stored bythe MSC 135, re-encrypt the data using a session key that is sharedbetween the MSC 135 and the security module 165, and send the encrypteddata to the security module 165 on the rendering device 160. Theexemplary authorization file's instructions can specify which keys theMSC 135 should use to decrypt data and encrypt data.

FIG. 2 illustrates an example media storage device 200, in accordancewith one or more implementations. The media storage device 200 can bethe same as the media storage device 131 in FIG. 1. The media storagedevice 200 can include a secure private section 201 and a public section203.

The public section 203 can include storage 260 usable to store mediadata 267 for one or more media items. For example, the media data 267can include data for Media-Title-1 to Media-Title-n. For each mediaitem, the media data 267 can include a media identifier (e.g.,Media-Title-1 261), an authorization file 265, and a data file 263 thatincludes the main data (e.g., encrypted video and audio) to be rendered.One implementation of an authorization file is described in greaterdetail below in conjunction with FIG. 3. The media data 267 can bereceived from one or more servers (e.g., authorization server 110 inFIG. 1, media server 115 in FIG. 1) of a content provider (e.g., contentprovider 103,105 in FIG. 1). If public section 203 is organized in afile system, the foregoing data on it can be stored in file(s) alongwith unrelated files.

The public section 203 can store certificate revision data 269. Thecertificate revision data 269 can be received from a key issuance server(e.g., key issuance server 160 in FIG. 1) and/or an authorization server(e.g., authorization server 110 in FIG. 1). The certificate revisiondata 269 (e.g., certificate revision lists) can include informationdescribing any revisions to the rights associated with the MSCs and/orrendering devices as described in the corresponding certificates. Thecertificates of the rendering devices include information describing,for example, and not limited to, the level of quality of media itemswhich the rendering device can render. For example, a Rendering-Device-Bmay have a certificate that allows Rendering-Device-B to render mediaitems in high-definition. If Rendering-Device-B is compromised (e.g.,hacked, attacked, etc.), the certificate revision list may includeinformation indicating that the certificate of Rendering-Device-B isrevised such that Rendering-Device-B is authorized to render media itemsin low-definition and not in high-definition.

The certificate revision data 269 can be updated whenever a newer validversion is available. For example, the certificate revision data 269 canbe updated when media items are downloaded to the media storage device200. In another example, the certificate revision data 269 can beupdated when the MSC 205 determines that the certificate revision data269 is outdated. For example, when the MSC 205 establishes a securesession with a rendering device, the MSC 205 and the rendering devicecan compare the versions of each other's certificate revision lists todetermine whether a certificate revision list is current or outdated.Digital signatures on certificate revision lists can authenticate boththe validity and freshness of the underlying data (e.g., an issuancedate or counter contained in the certificate revision list can enabledevices to identify if a new version is valid and newer than thecurrently-stored version).

The private section 201 can store base media storage device keys 252.The base media device storage keys 252 can be received from a keyissuance server (e.g., key issuance server 160 in FIG. 1) and stored inthe private data area 250 of the MSC 205, for example, when the mediastorage device 200 is manufactured. The base media device storage keys252 can include, for example, and are not limited to, an asymmetric keypair (e.g., RSA/ECC) and one or more AES keys. The base media storagedevice keys can be used in establishing a secure session with arendering device and/or with the authorization servers.

The private section 201 can be a secure section and can include a MSC205. The MSC 205 can store data 250 for protecting the media data 261and the media items (e.g., movies) relating to the media data 261. Thedata 250 can include authorization data 251 used as part of the processof rendering corresponding media items in storage 260. The authorizationdata 251 can include, for example, and is not limited to a list ofauthorization key slots to store the authorization keys, authorizationkey slot numbers, and information (e.g., publisher identifier,authorization identifier, authorization key, etc.) for each slot. Themedia storage device 200 can use the authorization keys in theauthorization data 251, for example, to decrypt data files 263 orportions of data files 263 or keys that have been used to encryptportions of data files 263 in the media data 267. The data 250 in theprivate storage can also include, for example, signatures, certificates,an internal key (e.g., in on-chip flash/fuses/OTP), the timestamp orserial number of the latest verified certificate revision list, etc.

The data 250 in the private section 201 can include a session key 253that is established between the MSC 205 and a security module (e.g.,security module 165 in FIG. 1) in a rendering device (e.g., renderingdevice 160 in FIG. 1) for a particular secure communication session. TheMSC 205 can use the session key 253 for securing communication with asecurity module (e.g., security module 165 in FIG. 1) in a renderingdevice. For example, the MSC 205 can receive data that is encryptedand/or authenticated by the security module and can use the session key253 to decrypt and/or verify the data. In another example, the MSC 205can encrypt and/or authenticate data using the session key 253 and cansend the encrypted data to the security module for decryption and/orverification.

As noted previously, in some embodiments, the MSC 205 may not be able todirectly access or interpret the media data 267 in the public section203 on the media storage device 200. For example, the MSC 205 may notunderstand the file system used to organize data on storage 260. Toobtain required data (such as portions of the media data 267), the MSC205 can send messages to the rendering device to retrieve the requiredmedia data 267 from the storage 260 and to provide the media data 267 tothe MSC 205. To ensure that the correct data is required, the MSC 205can digitally hash the returned data and confirm that the resulting hashmatches a digital signature and/or message authentication code.

For example, in one embodiment, when a movie (e.g., Media-Title-1 261)is selected to be rendered, the rendering device can retrieve theauthorization file 265 for the movie (e.g., Media-Title-1 261) from thepublic section 203 on the media storage device 200 and send theauthorization file 265 (or portions thereof) to the MSC 205. Theauthorization file portions can include one or more sets ofdigitally-signed instructions for the MSC 205 to execute. For example,an exemplary authorization file 265 for Media-Title-1 261 may include aset of instructions for the MSC 205 to derive a temporary key from abase media storage device key 271, use the temporary key to decrypt anencrypted key (which may also come from the authorization file 265)using a specified key in the instructions, then further decrypt theresult using an authorization key matching an ID designated in theinstructions. The exemplary instructions may then specify that the MSC205 should use session key 253 to re-encrypt the result and to send there-encrypted result to the security module on the rendering device. Theexemplary authorization file 265 contains instructions for securitymodule on the rendering device directing it to decrypt the re-encryptedresult using the session key and use the result as a key to renderportions of the data file 263 for the Media-Title-1 261 media item.

FIG. 3 illustrates example instructions in an example authorization file301 for protecting a media item using a media security controller,according to one exemplary implementation. The authorization file 301can be the same as the authorization file 265 in FIG. 2.

The authorization file 301 can include one or more sets of instructionsfor the security module and for the MSC to execute in connection withrendering a media item. For example, the MSC may receive instructions todecrypt Data-XYZ, re-encrypt Data-XYZ, and send the re-encryptedData-XYZ to the rendering device. In another example, the renderingdevice may receive instructions to wait to receive some data (i.e.,encrypted Data-XYZ) from the MSC and to decrypt the encrypted Data-XYZwhen the encrypted Data-XYZ is received.

The rendering device can include firmware for interpreting and executingthe instructions. For example, when a media item is selected forrendering, the firmware in the rendering device may instruct therendering device to automatically retrieve the authorization file 301for the selected media item and to forward the authorization file 301 orportions thereof to the MSC. The MSC can receive the authorization file301 or portions thereof from the rendering device and can authenticateand interpret the authorization file 301 or portions thereof.

There can be an authorization file 301 for each media item or a set ofmedia items. The authorization file 301 can be pre-encoded to includemedia identifiers (e.g., title identifiers), authorization identifiers,and one or more sets of operations 305 for rendering the correspondingmedia item. The instructions can be configurable, e.g. for thecorresponding media item(s). For example, a content provider (e.g.,publisher) can define the instructions and associated encrypted datavalues. The content provider can provide different instructions eachtime a new authorization file is issued (e.g., when a user downloadssome content and pays to have a license provided to the customer's mediastorage device). The set of operations 305 can include conditions orother branching/logic capabilities. For example, the set of operations305 may include a conditional statement that if bit 17=1, use the key ina specified authorization key slot to decrypt some data.

In one implementation, the individual sets of operations 305 are hashedby devices prior to being performed. The hash of the set of operations(hashes 307) themselves are hashed in a way that connects the variousindividual sets of operations 305 into a hash that (though variousstages of hashing) reflects all of the operations. In one embodiment,this is done with a hash tree. In another embodiment, operation setsinclude the hashes of subsequent operation sets. For example,OperationSet-1 (which has Hash-Value-1) references operations inOperationSet-2 and the reference in OperationSet-1 includes the hash ofOperationSet-2. OperationSet-2 may reference both OperationSet-3 andOperationSet-4, and those references would also include the hashes ofOperationSet-3 and OperationSet-4, respectively. In this way, a digitalsignature on Hash-Value-1 directly authenticates the contents ofOperationSet-1, which in turn authenticate the other OperationSets. Thenext instruction set may include Hash-Value-2 which confirms theintegrity of and chains to the next instruction set to execute, etc. Inboth of the foregoing embodiments, the total size of the instructionscarried in an authorization file 301 can be substantially larger thanthe RAM available in the MSC and/or the security module, since each ofthe MSC and the security module (in the rendering device) receive theirown portions of the instruction set and carry out the commands in theirportions.

Examples of commands that may be contained within the instruction setare shown below:

Examples of Sample Instruction Types:

Encrypt (who, key select, offset)

Compress (who, key select, offset)

Copy (who, src, dest, len)

Decrypt (who, key select, offset)

Compare (who, src, dest, len, jump location, hash of instruction set atjump location)

Fill (who, dest, len, data)

Finish (who, status)

Indirect Step (who, ptr, hash)

Transfer (who, src, dest, len)

AES (key select, offset [source], offset [destination])

AddToPlaybackMap (who [must be Security Module], key select, offset[with playback map data to append])

Offset in main encrypted content file on storage

Keys include separate keys for audio and video to apply

Length of data in encrypted content file

Destination in virtual content file

ReceiveData(ptr, length)

DeriveKey(key select [in], derivation parameters, key select [out])

Note: In the input parameters, “who” designates which entity shouldperform the instruction (e.g., MSC or Security Module), and may beomitted if operations for each are isolated into separate sets. “Keyselect” identifies a key in the entity that should be used in theprocessing. “Offset” specifies an offset (e.g., slot location or byteoffset) in a working area.

FIG. 4 is a diagram of an example of a media security controller 403interacting with a rendering device 405 to enable rendering of a mediaitem, according to various implementations. For example, the mediasecurity controller 403 and the rendering device 405 can establish asecure session, create a session key, and use the session key and otherkeys to create a playback map 465, which the rendering device 405 mayuse to render a media item. The media storage device 401 can be the sameas the media storage device 130 in FIG. 1 and media storage device 200in FIG. 2. The rendering device 405 can be the same as the renderingdevice 160 in FIG. 1.

The rendering device 405 may receive (420) a request to render a mediaitem that is stored in the data 451 in storage 450 on the media storagedevice 401. The request can be received as input of a user selection ofthe media item via a graphical user interface. For example, the requestmay be for Comedy-Movie-ABC. Either in response to, or prior to, therequest, the rendering device initiates a secure session between therendering device 405 and the media storage device 401.

In some embodiments, it is desirable that the newest availablecertificate revision list (CRL) be employed by both the media securitycontroller 403 on the media storage device 401 and security module 407on the rendering device 405. To enable synchronization of CRL versions,the MSC 403 and the security module 407 can each be configured toreceive a CRL header, then check if the header both: (i) has a valid adigital signature signed by a trusted entity (e.g., the key issuancecenter), (ii) has an issuance counter (or timestamp) indicating that theCRL is newer than the newest CRL previously seen. If both are true, thenewer CRL header is retained in a secure area and the entire CRL isstored on the destination device. If a newer CRL is being supplied tothe media, it can be written by the rendering device as a file in thepublic file system. If a newer CRL is being supplied to the renderingdevice, it can be read from the media's file system and stored in asmall flash, hard disk, or nonvolatile memory area in the renderingdevice. Thus, a process of synchronizing (421) certificate revisionlists and headers can include first checking whether the newest CRLversions seen by the devices are the same and, if not, sending from thedevice with the newer CRL the newer CRL to the device with the olderCRL. In addition, if desired, newer CRLs can also be sought over theInternet, from data on storage 451, or elsewhere (and, if a CRL is foundthat is newer than the latest seen by either device, then the new CRLshould be supplied to both devices, as described above). Upon completionof CRL synchronization 421, both devices will then have the same CRLversion.

At step 422, the media security controller 403 and the security module407 exchange certificates that respectively specify the renderingdevice/media storage device identity, type/manufacturer, attributes, andpublic key. The devices verify that the certificates are properlysigned, e.g. by verifying a chain of certificates initiating with thekey issuance center.

Each device verifies and processes (423) a certification revision listportion corresponding to the other's identity. The CRL portion receivedcan be compared against the CRL versions synchronized previously (421).Allowing CRLs to be in portions makes it simple to support CRL sizes inexcess of the amount of RAM available on constrained environments suchas MSC 403. In one embodiment, the rendering device 405 provides thenecessary portions from the certificate revision file to the mediasecurity controller 403 for the media security controller 403 to verifythe security module 407 identity. The MSC 403 can terminate the protocolif the received portion is not properly authenticated by a signatureissued by the key issuance center, if the version does not match theversion previously received, if the portion does not correspond to thesecurity module's certificates, or if the portion revokes securitymodule 407 (or otherwise makes security module 407 noncompliant with thecontent's requirements).

The MSC 403 stores (424) information from the certificate of therendering device 405. For example, the media storage device 401 mayallocate a fixed amount of memory (e.g., 16 Kbit) as buffer 453 and maypopulate the fixed sized buffer with the rendering device information(e.g., manufacturer, model, serial number, claimed class, revocationstatus from certificate revision list (CRL), revision status from CRL,etc.) from the certificate of the rendering device and/or thecorresponding CRL portion(s). Although not shown in the figure, securitymodule 407 likewise can form a buffer with information from the mediastorage device's certificates and/or corresponding CRL portion(s).

The MSC 403 and the security module 407 establish (425) a shared sessionkey using a handshake with a set of public keys and a handshake with aset of symmetric keys. This session key can correspond to session key253 in FIG. 2. The MSC 403 and the security module 407 can each deriveand store the session key locally. For example, each can encrypt arandom value with a public key from the other's certificate. The MSC 403and the security module 407 can then exchange these encrypted values,then each decrypts the other's value. The session key can then beproduced by hashing the decrypted results (e.g., hash(value encrypted bymedia ∥ media certificates ∥ value encrypted by rendering device ∥rendering device certificates), where “∥” denotes concatenation). “Hash”can be a cryptographic hash function, such as SHA-256.

The rendering device 405 then loads (427) the authorization file, andsends (429) the relevant authorization file portions to the MSC 403.

The MSC 403 identifies its first instruction set in the authorizationfile and begins to process (e.g., reads, executes, etc.) (430)instructions. Depending on the set of instructions, the MSC 403 may haveseveral iterations of exchanging and processing data with the securitymodule 407 on the rendering device 405. For example, the MSC 403 mayexecute a first set of instructions, which instruct the MSC 403 todecrypt data that is included in the instruction set. For example, theinstruction set may include an encrypted key and may specify theauthorization key in the MSC 403 that should be used to decrypt theencrypted key.

The exemplary instruction set for the MSC in FIG. 4 includes aninstruction for the MSC 403 to receive additional data from therendering device 405. To process this instruction, the MSC 403 sends(431) a message to the security module 407 for the security module 407to obtain additional data from the security module 407. The securitymodule 407 retrieves (433) the data (e.g., from the storage 450 asshown, or other sources such as rendering device's internal memory, fromthe Internet, etc.) and sends (435) the data to the MSC 403 (or respondswith an error). The MSC 403 processes 437 (e.g., decrypts and/orencrypts using keys produced earlier, such as during step 430) the dataand sends (439) the processed data to the security module 407 (e.g., byproviding the data to the rendering device which passes it along to thesecurity module). The security module 407 processes (441) the receiveddata. For example, the security module 407 may also receive further setsof instructions from the authorization file describing how the securitymodule 407 should process the data. For example, the security module 407can use a session key 460 to decrypt the received data, then apply afurther decryption step using a key derived from a key from the keyissuance center (see key distribution 149 in FIG. 1) and can store theresult as part of data 467.

In another example, the security module 407 can use a session key 460 todecrypt the data and can store the decrypted data as part of theplayback map 465. For example, the authorization file can includeinstructions for the security module 407 to write data (e.g., decryptedkey, offset value, length, etc.) to a buffer that stores the playbackmap 465. The data placed in the playback map 465 can, withoutlimitation, be derived using data received from the MSC 403, data fromstorage 450, data from media device certificates, data from renderingdevice certificates, data from CRLs, data from instructions, dataretrieved from networks (such as the Internet), and any other data thatmay be available. For example, information from any of these sources canbe used to select playback map entries that select among differentalternate portions of the content (e.g. to achieve forensic marking).The sets of instructions associated with a title allow flexibility inhow a given title will be decoded, and through this process the securitymodule 407 can use data from many sources, and it may incrementallyand/or iteratively receive data from the MSC 403 to construct theplayback map 465.

For example, the authorization file may include instructions for thesecurity module 407 to add an operation to the playback map 465. Theoperation can be executed by the security module 407. The playback mapentry may also call for additional processing. For example, the entrymay instruct the rendering device 405 and/or its security module 407 tointerface with the MSC 403 at a point in time during rendering of themedia item to receive assistance from the MSC 403, e.g. to convert aprecursor value into a key that can then be used in rendering a portionof the media item.

For example, at communication 439, the authorization file can instructthe security module 407 to add an operation to the playback map 465 thatrequires communication with the MSC 403 when rendering the media itemfrom offset range X through Y in the media item. The operation caninclude parameters, such as, and not limited to, an indicator to triggercommunication by the security module 407 with the MSC 403, an offset, alength, etc. The assistance may be, for example, that the MSC 403 shoulddecrypt the media file data at offsets X through Y.

The playback map 465 can be constructed using multiple communicationsfrom the MSC 465. For example, communications 431,433 may includeinstructions for the security module 407 to write to the playback map465. For example, the instructions may direct the security module 407 towrite to the playback map 465 an entry containing a Length, an Offset inthe storage, and a Key Value. For example, the instructions may be forthe security module 407 to write “The next [Length] bytes of the mediashould be read starting at offset [Offset] in the media file on thestorage and should be decrypted with the key [Key Value]” to theplayback map 465. In an alternate embodiments, other methods orencodings for specifying and selecting among different keys across themedia item may be utilized, or there may be a single key for the entiremedia item.

The rendering device 405 can use the playback map 465 to render themedia items. The playback map 465 can include information about how tolocate and decrypt ciphertext making up the item, and is used by thesecurity module 407 to form, decrypt, and render the media item. Theplayback map 465 can include (but is not limited to) the one or morekeys that the rendering device 405 should use to decrypt the media item.When the rendering device 405 reads the data file for the media itemfrom storage 450 and reaches a portion of the data file to be decrypted,the rendering device 405 can use a corresponding key in the playback map465 to decrypt the portion of data. In another example, when therendering device 405 reaches a portion of the data file to be decrypted,the rendering device 405 may read an instruction in the playback map 465to contact the MSC 403 to help decrypt the portion of the data.Decryption of the data can use conventional cryptographic methods, suchas AES in counter mode.

In one implementation, the security module 407 can start rendering amedia item using a partially constructed playback map 465 and cancontinue to construct the playback map 465 based on furthercommunications from the MSC 403. For example, the MSC 403 and thesecurity module 407 can establish a secure session and can partiallyconstruct a playback map 465. The rendering device 405 may start torender the media item (e.g., movie) based on the partially constructedplayback map 465. At various points while the rendering device 405 isplaying a movie, the rendering device 405 may detect a portion of datawhich the rendering device 405 cannot decrypt and can interface with themedia security module 403 to decrypt the portion of data. Rendering canalso begin before the media item is completely downloaded, provided thatthe required data is present.

Content providers (e.g., publishers) may wish to identify which MSCand/or rendering device rendered a media item. For example, publishersmay become aware of unauthorized copies of media items and/or devices(e.g., media storage devices, rendering devices) and may wish to tracewhich MSCs and/or rendering devices are associated with the unauthorizedcopies. Content providers can use the instructions in the authorizationfiles and the execution of the instructions by the MSCs and/or renderingdevices for forensic analysis to identify which MSCs and/or renderingdevices rendered particular media items.

For example, content providers can select keys for decryption forparticular media security controllers and/or rendering devices. When arendering device and/or media security controller decrypts a media item,the result can vary depending on whether the authorized key was used.For example, the content providers can define and pre-encode theauthorization files with instructions such that when a portion of amovie is played, different rendering devices have different playback mapentries (e.g., one player may play generate key K1 in the playback mapand use it to decrypt variant A of the portion, while another player maygenerate key K2 in the playback map and use it to decrypt variant B ofthe portion). If a pirated copy is recovered, the variant in the fileconveys information about the pirate (e.g., if variant A is present thenthe pirate was able to decrypt variant A, if variant B is present thenthe pirate was able to decrypt variant B). Given enough variants, it ispossible to convey any information. The size of a variant can be assmall as a few bytes in the compressed video, or variants can be muchlonger (such as significant portions of video or audio data).

FIG. 5 is a diagram of an example of a rendering device 505 using aplayback map 565 and a media security controller (MSC) 503 to render amedia item, according to various implementations. For example, an entryin the playback map 565 may instruct the rendering device 505 to seekassistance from the MSC 503 to render a corresponding portion of themedia item (e.g., movie). In this way, the MSC 503 may activelyparticipate during the rendering of the media item by decrypting aportion of the media item or by providing the rendering device with akey that can be used to decrypt at least the portion of the media item.The media storage device 501 can be the same as the media storage device130 in FIG. 1 and media storage device 200 in FIG. 2. The renderingdevice 505 can be the same as the rendering device 160 in FIG. 1.

The security module 507 on the rendering device 505 reads (520) an entryin a playback map 565 that is stored in the rendering device 505. In theexample shown in FIG. 5, the entry specifies that processing by the MSC503 is required for the data. The rendering device 505 reads the datafrom the public storage area by issuing (521) a request (e.g., a fileread) then receives (522) the required data. Part or all of the data isthen sent 523 to the MSC 503 with a request that designates theprocessing required (e.g., how the MSC 503 should decrypt the data). TheMSC 503 performs (524) the requested processing and returns (525) theresult back to the rendering device 505. The rendering device 505 canperform further processing (526) of its own, such as using the MSC 503to apply an additional decryption pass on the data. Finally, the data isready to be rendered. The rendering device decodes 527 the video/audio,e.g. by sending portion(s) of the data to audio or video codecs fordecompression and output

FIG. 6 illustrates example key management commands 600 for protectingauthorization keys in a media security controller, according to variousimplementations. Such keys can be used to secure the removal andtransfer of authorizations, e.g. if an authorization is to betransferred from one media device to another, the process can consistof: (1) disabling the authorization key on the source device, (2)confirming to an authorization server that the key is disabled, (3) theauthorization server issuing a new authorization file and newauthorization key for the destination media device. Authorization keyscan also help verify that the content is properly authorized, e.g. tohelp prevent duplication of authorizations (since only the authorizedmedia device should have the correct authorization key). The keymanagement commands 600 can be used, for example, by a server, renderingdevice, etc. For example, an authorization server (e.g., authorizationserver 110 in FIG. 1) can use one or more of the key management commandsto provision authorization keys to MSCs and to manage the authorizationkeys that are stored by the MSCs.

For example, when a media item is purchased, the authorization servercan send an authorization file for the media item, a data file for themedia item, and an authorization key corresponding to the media item tothe media storage device. The authorization server can also send a“Manage K_(Authorization)” command 603 to the MSC on the media storagedevice. This command 603 can direct the MSC to receive, verify, andstore a specified authorization key. For example, the manage command 603may specify to the MSC the authorization key to store, the authorizationidentifier to store, and the slot number to use to store theauthorization key, and other authorization-related information.

In this example, a rendering device may use one or more of the keymanagement commands 600 as part of the playback process. For example, arendering device (e.g., rendering device 160 in FIG. 1) may use the usethe “Read Slot” command 602 to verify that there is already anauthorization key in the MSC for a particular media item. During theplayback process, the instructions performed by the MSC (e.g. such asthose in part of 430 in FIG. 4, or the processing in connection withplayback entries such as 524 in FIG. 5) can utilize the authorizationkey, e.g. to ensure that playback cannot be performed on unauthorizedmedia or media from which the authorization has been removed.

The authorization servers can establish secure communications with theMSCs. A key issuance server can issue base media storage device keys tothe MSCs. In one implementation the key issuance server uses a key treeto create a derived list of keys that are derived from the base mediastorage device keys that are issued to the MSCs. The key issuance servercan provide the list of derived keys to the authorization server. Theauthorization server can have secure communications with the MSCs usingthe list of derived keys. The use of the derived keys allows theauthorization server to securely communicate with the MSCs withoutactually having knowledge of the base media storage device keys that areassigned to the MSCs (e.g., to prevent the compromise of oneauthorization server from compromising operations performed by the mediaand other authorization servers).

In one implementation the key issuance server creates the derived keysusing a key tree function that has, as inputs, the base media storagedevice keys that are assigned to the MSCs and the publisher identifiersassociated with the authorization servers. For example, the derived keysmay be computed with input parameters of (base media storage device key,publisherID). The derived keys can be shared between the correspondingMSC and authorization server. The individual content providers (e.g.,publishers) can receive a list of derived keys which allowscommunications between the authorization servers of the contentproviders and the MSCs.

FIG. 7, described in greater detail below, is a block diagram of anexample computer system that is configured to perform one or more of theoperations of a media security controller described herein, inaccordance with various implementations. FIG. 8, described in greaterdetail below, is a block diagram of an example computer system that isconfigured to perform one or more of the operations of a security moduledescribed herein, in accordance with various implementations. In someembodiments, the computer systems of FIG. 7 and FIG. 8 are embodied in asingle system configured to perform both the operations of a mediasecurity controller and a security module.

FIG. 7 illustrates a diagram of a machine in an example form of acomputer system 700 within which a set of instructions, for causing themachine to perform any one or more of the methodologies of a mediasecurity controller discussed herein, may be executed. In alternativeimplementations, the machine may be connected (e.g., networked) to othermachines in a LAN, an intranet, an extranet, or the Internet. Themachine may operate in the capacity of a server or a client machine inclient-server network environment, or as a peer machine in apeer-to-peer (or distributed) network environment. The machine may be apersonal computer (PC), a tablet PC, a set-top box (STB), a PersonalDigital Assistant (PDA), a cellular telephone, a web appliance, aserver, a network router, switch or bridge, or any machine capable ofexecuting a set of instructions (sequential or otherwise) that specifyactions to be taken by that machine. Further, while only a singlemachine is illustrated, the term “machine” shall also be taken toinclude any collection of machines, chips, and/or microprocessors thatindividually or jointly execute a set (or multiple sets) of instructionsto perform any one or more of the methodologies discussed herein.

The example computer system 700 includes a processing device (processor)702, a main memory 704 (e.g., read-only memory (ROM), flash memory,dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM),double data rate (DDR SDRAM), or DRAM (RDRAM), etc.), a static memory706 (e.g., flash memory, static random access memory (SRAM), etc.), anda data storage device 614, which communicate with each other via a bus730.

Processor 702 represents one or more general-purpose processing devicessuch as a microprocessor, central processing unit, or the like. Moreparticularly, the processor 702 may be a complex instruction setcomputing (CISC) microprocessor, reduced instruction set computing(RISC) microprocessor (including without limitation an embedded CPU corerunning the ARM or MIPS instruction set), very long instruction word(VLIW) microprocessor, or a processor implementing other instructionsets or processors implementing a combination of instruction sets. Theprocessor 702 may also be one or more special-purpose processing devicessuch as an application specific integrated circuit (ASIC), a fieldprogrammable gate array (FPGA), a digital signal processor (DSP),network processor, or the like. The processor 702 is configured toexecute instructions 722 for performing operations and steps discussedherein. The instructions 722 may also reside, completely or at leastpartially, within the main memory 704 and/or within the processor 702during execution thereof by the computer system 700, the main memory 704and the processor 702 also constituting computer-readable storage media.The instructions 722 may further be transmitted or received over anetwork 720 via the network interface device 708. Instructions 722 (orother instructions associated with the present invention) may bedigitally signed (or otherwise cryptographically authenticated), andverified prior to execution (e.g. by processor 702).

The computer system 700 may further include a network interface device708. The computer system 700 also may include a video display unit 710(e.g., a liquid crystal display (LCD) or a cathode ray tube (CRT)), aninput device 712 (e.g., a keypad, a touchscreen, an alphanumerickeyboard, a motion sensing input device, etc.), a cursor control device714 (e.g., a mouse), and/or a signal generation device 716 (e.g., aspeaker).

The data storage device 718 may include a computer-readable storagemedium 728 on which is stored one or more sets of instructions 723(e.g., software) embodying any one or more of the methodologies orfunctions of a media security controller described herein. In oneimplementation, the data storage device 718 may include acomputer-readable storage medium 728 on which is stored one or more setsof instructions 723 embodying any one or more of the methodologies orfunctions of a media security controller module described herein. Whilethe computer-readable storage medium 728 (machine-readable storagemedium) is shown in an exemplary implementation to be a single medium,the term “computer-readable storage medium” should be taken to include asingle medium or multiple media (e.g., RAID array, network-attachedstorage device, flash memories, a centralized or distributed database,and/or associated caches and servers, etc.) that store the one or moresets of instructions. The term “computer-readable storage medium” shallalso be taken to include any medium that is capable of storing, encodingor carrying a set of instructions for execution by the machine and thatcause the machine to perform any one or more of the methodologies of thepresent disclosure. The term “computer-readable storage medium” shallaccordingly be taken to include, but not be limited to, solid-statememories, optical media, and magnetic media.

FIG. 8 illustrates a diagram of a machine in an example form of acomputer system 800 within which a set of instructions, for causing themachine to perform any one or more of the methodologies of a securitymodule discussed herein, may be executed. In alternativeimplementations, the machine may be connected (e.g., networked) to othermachines in a LAN, an intranet, an extranet, or the Internet. Themachine may operate in the capacity of a server or a client machine inclient-server network environment, or as a peer machine in apeer-to-peer (or distributed) network environment. The machine may be apersonal computer (PC), a tablet PC, a set-top box (STB), a PersonalDigital Assistant (PDA), a cellular telephone, a web appliance, aserver, a network router, switch or bridge, or any machine capable ofexecuting a set of instructions (sequential or otherwise) that specifyactions to be taken by that machine. Further, while only a singlemachine is illustrated, the term “machine” shall also be taken toinclude any collection of machines, chips, and/or microprocessors thatindividually or jointly execute a set (or multiple sets) of instructionsto perform any one or more of the methodologies discussed herein.

The example computer system 800 includes a processing device (processor)802, a main memory 804 (e.g., read-only memory (ROM), flash memory,dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM),double data rate (DDR SDRAM), or DRAM (RDRAM), etc.), a static memory806 (e.g., flash memory, static random access memory (SRAM), etc.), anda data storage device 818, which communicate with each other via a bus830.

Processor 802 represents one or more general-purpose processing devicessuch as a microprocessor, central processing unit, or the like. Moreparticularly, the processor 802 may be a complex instruction setcomputing (CISC) microprocessor, reduced instruction set computing(RISC) microprocessor (including without limitation an embedded CPU corerunning the ARM or MIPS instruction set), very long instruction word(VLIW) microprocessor, or a processor implementing other instructionsets or processors implementing a combination of instruction sets. Theprocessor 802 may also be one or more special-purpose processing devicessuch as an application specific integrated circuit (ASIC), a fieldprogrammable gate array (FPGA), a digital signal processor (DSP),network processor, or the like. The processor 802 is configured toexecute instructions 822 for performing operations and steps discussedherein. Processor 802, or other hardware and/or software in the system,implements the capabilities of the security module 165.

The computer system 800 may further include a network interface device808. The computer system 800 also may include a video display unit 810(e.g., a liquid crystal display (LCD) or a cathode ray tube (CRT)), aninput device 812 (e.g., a keypad, a touchscreen, an alphanumerickeyboard, a motion sensing input device, etc.), a cursor control device814 (e.g., a mouse), and/or a signal generation device 816 (e.g., aspeaker).

In one implementation, the data storage device 818 may include acomputer-readable storage medium 828 on which is stored one or more setsof instructions 822 (e.g., software) embodying any one or more of themethodologies or functions of a security module described herein. Theinstructions 822 may also reside, completely or at least partially,within the main memory 804 and/or within the processor 802 duringexecution thereof by the computer system 800, the main memory 804 andthe processor 802 also constituting computer-readable storage media. Theinstructions 822 may further be transmitted or received over a network820 via the network interface device 808.

In one implementation, the instructions 822 include instructions for asecurity module (e.g., security module 165 in FIG. 1), and/or a softwarelibrary containing methods that call the security module. While thecomputer-readable storage medium 828 (machine-readable storage medium)is shown in an exemplary implementation to be a single medium, the term“computer-readable storage medium” should be taken to include a singlemedium or multiple media (e.g., RAID array, network-attached storagedevice, flash memories, a centralized or distributed database, and/orassociated caches and servers) that store the one or more sets ofinstructions. The term “computer-readable storage medium” shall also betaken to include any medium that is capable of storing, encoding orcarrying a set of instructions for execution by the machine and thatcause the machine to perform any one or more of the methodologies of thepresent disclosure. The term “computer-readable storage medium” shallaccordingly be taken to include, but not be limited to, solid-statememories, optical media, and magnetic media.

In various embodiments, media connects to the rendering device via, forexample, and not limited to, USB, SD/SDHC/SDXC/etc., SCSI, SATA, andEthernet protocols. The connection may be wired or wireless. Any filesystem can be used on the storage device, including FAT32, NFS, NTFS,RiserFS, etc. The communications involving “special” securedtransactions can be handled via out-of-band control operations, orintegrated with the bulk data transfer operations that are part oflegacy file system operation. Media devices that implement this systemcan be fully backward compatible, e.g. ordinary consumer hard drives,flash cards, USB drives. Likewise, rendering devices that implement thiscan support other playback methods as well, such as Internet streaming,playback from optical drives, etc.]

In the foregoing description, numerous details are set forth. It will beapparent, however, to one of ordinary skill in the art having thebenefit of this disclosure, that the present disclosure may be practicedwithout these specific details. In some instances, well-known structuresand devices are shown in block diagram form, rather than in detail, inorder to avoid obscuring the present disclosure.

Some portions of the detailed description have been presented in termsof algorithms and symbolic representations of operations on data bitswithin a computer memory. These algorithmic descriptions andrepresentations are the means used by those skilled in the dataprocessing arts to most effectively convey the substance of their workto others skilled in the art. An algorithm is here, and generally,conceived to be a self-consistent sequence of steps leading to a desiredresult. The steps are those requiring physical manipulations of physicalquantities. Usually, though not necessarily, these quantities take theform of electrical or magnetic signals capable of being stored,transferred, combined, compared, and otherwise manipulated. It hasproven convenient at times, for reasons of common usage, to refer tothese signals as bits, values, elements, symbols, characters, terms,numbers, or the like.

It should be borne in mind, however, that all of these and similar termsare to be associated with the appropriate physical quantities and aremerely convenient labels applied to these quantities. Unlessspecifically stated otherwise as apparent from the following discussion,it is appreciated that throughout the description, discussions utilizingterms such as “sending”, “receiving”, “transforming”, “decrypting”,“encrypting”, “compressing”, “performing”, “establishing”, “creating”,“rendering”, “processing”, or the like, refer to the actions andprocesses of a computer system, or similar electronic computing device,that manipulates and transforms data represented as physical (e.g.,electronic) quantities within the computer system's registers andmemories into other data similarly represented as physical quantitieswithin the computer system memories or registers or other suchinformation storage, transmission or display devices.

For simplicity of explanation, the methods are depicted and describedherein as a series of acts. However, acts in accordance with thisdisclosure can occur in various orders and/or concurrently, and withother acts not presented and described herein. Furthermore, not allillustrated acts may be required to implement the methods in accordancewith the disclosed subject matter. In addition, those skilled in the artwill understand and appreciate that the methods could alternatively berepresented as a series of interrelated states via a state diagram orevents. Additionally, it should be appreciated that the methodsdisclosed in this specification are capable of being stored on anarticle of manufacture to facilitate transporting and transferring suchmethods to computing devices. The term article of manufacture, as usedherein, is intended to encompass a computer program accessible from anycomputer-readable device or storage media.

Certain implementations of the present disclosure also relate to anapparatus for performing the operations herein. This apparatus may beconstructed for the intended purposes, or it may comprise a generalpurpose computer selectively activated or reconfigured by a computerprogram stored in the computer. Such a computer program may be stored ina computer readable storage medium, such as, but not limited to, anytype of disk including floppy disks, optical disks, CD-ROMs, andmagnetic-optical disks, read-only memories (ROMs), random accessmemories (RAMs), EPROMs, EEPROMs, magnetic or optical cards, or any typeof media suitable for storing electronic instructions.

Reference throughout this specification to “one implementation” or “animplementation” means that a particular feature, structure, orcharacteristic described in connection with the implementation isincluded in at least one implementation. Thus, the appearances of thephrase “in one implementation” or “in an implementation” in variousplaces throughout this specification are not necessarily all referringto the same implementation. In addition, the term “or” is intended tomean an inclusive “or” rather than an exclusive “or.” Moreover, thewords “example” or “exemplary” are used herein to mean serving as anexample, instance, or illustration. Any aspect or design describedherein as “exemplary” is not necessarily to be construed as preferred oradvantageous over other aspects or designs. Rather, use of the words“example” or “exemplary” is intended to present concepts in a concretefashion.

It is to be understood that the above description is intended to beillustrative, and not restrictive. Many other implementations will beapparent to those of skill in the art upon reading and understanding theabove description. The scope of the disclosure should, therefore, bedetermined with reference to the appended claims, along with the fullscope of equivalents to which such claims are entitled.

The following examples pertain to further embodiments.

Example 1 is an apparatus for protecting a media item using a mediasecurity controller comprising 1) a memory to store a media item anddata relating to rendering the media item by a rendering device; and 2)a media security controller comprising a processing device coupled tothe memory to send to a rendering device, in response to the renderingdevice reading an authorization file, a message for the rendering deviceto read a portion of the data from the memory and to provide the portionof data to the media security controller, receive the portion of thedata from the rendering device, transform the portion of the data, andsend the transformed portion of the data to the rendering device.

In Example 2, the transformed portion of the data in the subject matterof Example 1 can optionally comprise data for the rendering device torender the media item.

In Example 3, the media security controller in the subject matter ofExample 1 can optionally transform the portion of the data by at leastone of decrypting the portion of the data, encrypting the portion of thedata, or compressing the portion of the data.

In Example 4, the media security controller in the subject matter ofExample 1 can optionally further comprises a second memory to store anauthorization key corresponding to the transformed portion of the data.

In Example 5, the processing device in the subject matter of Example 4can optionally further decrypt the portion of the data using theauthorization key.

In Example 6, the media security controller in the subject matter ofExample 1 can optionally perform a first handshake with the renderingdevice based on public key infrastructure cryptography, perform a secondhandshake with the rendering device based on symmetric key cryptography,and establish a secure session with the rendering device based on thefirst handshake and the second handshake.

In Example 7, the media security controller in the subject matter ofExample 1 can optionally transform the portion of the data by receivinga set of instructions specifying an authorization key for transformingthe portion of the data, wherein the set of instructions enable forensicanalysis to identify the media security controller to a third party, andcreating the transformed portion of the data using the authorizationkey, wherein the transformed portion of the data identifies the mediasecurity controller to the third party.

In Example 8, the media security controller in the subject matter ofExample 1 can optionally synchronize a first certificate revision listof the media security controller with a second certificate revision listof the rendering device, wherein the first certificate revision list andthe second certificate revision list describe one or more changes to aset of rights.

Various embodiments may have different combinations of the operationalfeatures described above. For instance, all optional features of theapparatus described above may also be implemented with respect to themethod or process described herein and specifics in the examples may beused anywhere in one or more embodiments.

Example 9 is a method for protecting a media item using a media securitycontroller comprising 1) sending to a rendering device, by the mediasecurity controller in response to the rendering device reading anauthorization file, a message for the rendering device to read a portionof data from a memory of a media storage device and to provide theportion of the data to the media security controller, wherein the datain the memory of the media storage device relates to a media item to berendered by the rendering device; 2) receiving from the renderingdevice, by the media security controller, the portion of the data; 3)transforming, by the media security controller, the portion of the data;and 4) sending to the rendering device, by the media securitycontroller, the transformed portion of the data.

In Example 10, the transformed portion of the data in the subject matterof Example 9 can optionally comprise data for the rendering device torender the media item.

In Example 11, the transforming of the portion of the data in thesubject matter of Example 9 can optionally comprise at least one ofdecrypting the portion of the data, encrypting the portion of the data,or compressing the portion of the data.

In Example 12, the media security controller in the subject matter ofExample 9 can optionally comprise a second memory to store anauthorization key corresponding to the transformed portion of the data.

In Example 13, the transforming of the portion of data in the subjectmatter of Example 12 can optionally comprise decrypting, by the mediasecurity controller, the portion of the data using the authorizationkey.

In Example 14, the subject matter of Example 9 can optionally furthercomprise performing a first handshake between the media securitycontroller and the rendering device based on public key infrastructurecryptography, performing a second handshake between the media securitycontroller and the rendering device based on symmetric key cryptography,and establishing a secure session with the rendering device based on thefirst handshake and the second handshake.

In Example 15, the transforming of the portion of data in the subjectmatter of Example 9 can optionally comprise receiving, by the mediasecurity controller, a set of instructions specifying an authorizationkey for transforming the portion of the data, wherein the set ofinstruction enable forensic analysis to identify the media securitycontroller to a third party, and creating, by the media securitycontroller, the transformed portion of the data using the authorizationkey, wherein the transformed portion of data identifies the mediasecurity controller to the third party.

In Example 16, the subject matter of Example 9 can optionally furthercomprise synchronizing a first certificate revision list of the mediasecurity controller with a second certificate revision list of therendering device, wherein the first certificate revision list and thesecond certificate revision list describe one or more changes to a setof rights.

Various embodiments may have different combinations of the operationalfeatures described above. For instance, all optional features of themethod described above may also be implemented with respect to anon-transitory, computer-readable storage medium. Specifics in theexamples may be used anywhere in one or more embodiments.

Examples 17-24 are a non-transitory, computer-readable storage mediumincluding instructions that, when executed by a computing system, causethe computing system to perform the operations of Examples 9-16.

Various embodiments may have different combinations of the operationalfeatures described above. For instance, all optional features of themethod described above may also be implemented with respect to anapparatus. Specifics in the examples may be used anywhere in one or moreembodiments.

Examples 25-32 are a system for protecting a media item using a mediasecurity controller comprising means for executing the operations ofExamples 9-16.

Example 33 is an apparatus for protecting a media item using a mediasecurity controller comprising 1) a memory to store data to render themedia item; and 2) a processing device coupled to the memory to receivea message, from the media security controller in response to theprocessing device reading an authorization file, to read a portion ofthe data from the memory and to provide the portion of the data to themedia security controller, send the portion of the data to the mediasecurity controller, and receive a transformed portion of the data fromthe media security controller.

In Example 34, the processing device in the subject matter of Example 33can optionally further create a playback map based on the transformedportion of the data received from the media security controller, whereinthe playback map comprises data to render the media item.

In Example 35, the processing device in the subject matter of Example 33can optionally further render the media item based on the transformedportion of the data received from the media security controller.

In Example 36, the processing device in the subject matter of Example 33can optionally further process the transformed portion of the data usinga session key that is shared with the media storage device.

In Example 37, the processing device in the subject matter of Example 36can optionally process the transformed portion of the data by at leastone of decrypting the transformed portion of the data, encrypting thetransformed portion of the data, or compressing the transformed portionof the data. In Example 38, the processing device in the subject matterof Example 33 can optionally further perform a first handshake with themedia security controller based on public key infrastructurecryptography; perform a second handshake with the media securitycontroller based on symmetric key cryptography; and establish a securesession with the media security controller based on the first handshakeand the second handshake.

In Example 39, the processing device in the subject matter of Example 33can optionally further synchronize a first certificate revision list ofthe with a second certificate revision list of the media securitycontroller, wherein the first certificate revision list and the secondcertificate revision list describe one or more changes to a set ofrights.

Various embodiments may have different combinations of the operationalfeatures described above. For instance, all optional features of theapparatus described above may also be implemented with respect to themethod or process described herein and specifics in the examples may beused anywhere in one or more embodiments.

Example 40 is a method for protecting a media item using a mediasecurity controller comprising 1) receiving, by a rendering device, amessage from the media security controller in response to the renderingdevice reading an authorization file, the message instructing therendering device to read a portion of data from a memory of a mediastorage device and to provide the portion of the data to the mediasecurity controller, wherein the data in the memory of the media storagedevice relates to a media item to be rendered by the rendering device;2) sending, by the rendering device, the portion of the data to themedia security controller; and 3) receiving, by the rendering device, atransformed portion of the data from the media security controller.

In Example 41, the subject matter of Example 40 can optionally furthercomprise creating a playback map based on the transformed portion of thedata received from the media security controller, wherein the playbackmap comprises data to render the media item.

In Example 42, the subject matter of Example 40 can optionally furthercomprise rendering the media item based on the transformed portion ofthe data received from the media security controller.

In Example 43, the subject matter of Example 40 can optionally furthercomprise processing the transformed portion of the data using a sessionkey that is shared with the media storage device.

In Example 44, the processing of the transformed portion of the data inthe subject matter of Example 43 can optionally comprise at least one ofdecrypting the transformed portion of the data, encrypting thetransformed portion of the data, or compressing the transformed portionof the data.

In Example 45, the subject matter of Example 40 can optionally furthercomprise performing a first handshake with the media security controllerbased on public key infrastructure cryptography, perform a secondhandshake with the media security controller based on symmetric keycryptography, and establishing a secure session with the media securitycontroller based on the first handshake and the second handshake.

In Example 46, the subject matter of Example 40 can optionally furthercomprise synchronizing a first certificate revision list of therendering device with a second certificate revision list of the mediasecurity controller, wherein the first certificate revision list and thesecond certificate revision list describe one or more changes to a setof rights.

Various embodiments may have different combinations of the operationalfeatures described above. For instance, all optional features of themethod described above may also be implemented with respect to anon-transitory, computer-readable storage medium. Specifics in theexamples may be used anywhere in one or more embodiments.

Examples 47-53 are a non-transitory, computer-readable storage mediumincluding instructions that, when executed by a computing system, causethe computing system to perform the operations of Examples 40-46.

Various embodiments may have different combinations of the operationalfeatures described above. For instance, all optional features of themethod described above may also be implemented with respect to anapparatus. Specifics in the examples may be used anywhere in one or moreembodiments.

Examples 54-60 are a system for protecting a media item using a mediasecurity controller comprising means for executing the operations ofExamples 40-46.

Example 61 is an apparatus for revising rights defined in a certificatecomprising 1) a memory to store a certificate; and 2) a processingdevice coupled to the memory to identify a set of rights in acertificate, identify a change to the set of rights, create acertificate revision list describing the change to the set of rights,and distribute the certificate revision list.

In Example 62, the change in the subject matter of Example 61 canoptionally pertain to a level of quality for rendering a media item.

In Example 63, the set of rights in the subject matter of Example 61 canoptionally describe one or more rights assigned to at least one of amedia security controller or a rendering device.

In Example 64, the certificate revision list in the subject matter ofExample 61 can optionally comprise a version identifier.

Various embodiments may have different combinations of the operationalfeatures described above. For instance, all optional features of theapparatus described above may also be implemented with respect to themethod or process described herein and specifics in the examples may beused anywhere in one or more embodiments.

Example 65 is a method for revising rights defined in a certificatecomprising 1) identifying a set of rights in a certificate; 2)identifying a change to the set of rights; 3) creating, by a computersystem, a certificate revision list describing the change to the set ofrights; and 4) distributing the certificate revision list.

In Example 66, the change in the subject matter of Example 65 canoptionally pertain to a level of quality for rendering a media item.

In Example 67, the set of rights in the subject matter of Example 65 canoptionally describe one or more rights assigned to at least one of amedia security controller or a rendering device.

In Example 68, the certificate revision list in the subject matter ofExample 65 can optionally comprise a version identifier.

Various embodiments may have different combinations of the operationalfeatures described above. For instance, all optional features of themethod described above may also be implemented with respect to anon-transitory, computer-readable storage medium. Specifics in theexamples may be used anywhere in one or more embodiments.

Examples 69-72 are a non-transitory, computer-readable storage mediumincluding instructions that, when executed by a computing system, causethe computing system to perform the operations of Examples 65-68.

Various embodiments may have different combinations of the operationalfeatures described above. For instance, all optional features of themethod described above may also be implemented with respect to anapparatus. Specifics in the examples may be used anywhere in one or moreembodiments.

Examples 73-76 are a system for revising rights defined in a certificatecomprising means for executing the operations of Examples 65-68.

Example 77 is an apparatus for revising rights of a device using acertificate revision list comprising 1) a memory to store a certificate;and 2) a processing device coupled to the memory to identify the deviceto perform an action pertaining to rendering a media item, identify acertificate describing a set of rights that are assigned to the device,identify a change to the set of rights in the certificate revision list,and allow the device to perform the action to render the media itembased on the change in the certificate revision list.

In Example 78, the processing device in the subject matter of Example 77can optionally further determine whether the certificate revision listis outdated and receive a current certificate revision list based on adetermination that the certificate revision list is outdated.

In Example 79, the change in the subject matter of Example 77 canoptionally pertain to a level of quality for rendering a media item.

In Example 80, the set of rights in the subject matter of Example 77 canoptionally describe one or more rights assigned to at least one of amedia security controller or a rendering device.

In Example 81, the certificate revision list in the subject matter ofExample 77 can optionally comprise a version identifier.

Various embodiments may have different combinations of the operationalfeatures described above. For instance, all optional features of theapparatus described above may also be implemented with respect to themethod or process described herein and specifics in the examples may beused anywhere in one or more embodiments.

Example 82 is a method for revising rights of a device using acertificate revision list comprising 1) identifying a device to performan action pertaining to rendering a media item; 2) identifying acertificate describing a set of rights that are assigned to the device;3) identifying a change to the set of rights in a certificate revisionlist; and 4) allowing the device to perform the action to render themedia item based on the change in the certificate revision list.

In Example 83, the subject matter of Example 82 can optionally furthercomprise determining whether the certificate revision list is outdatedand receiving a current certificate revision list based on adetermination that the certificate revision list is outdated.

In Example 84, the change in the subject matter of Example 82 canoptionally pertain to a level of quality for rendering a media item.

In Example 85, the set of rights in the subject matter of Example 82 canoptionally describe one or more rights assigned to at least one of amedia security controller or a rendering device.

In Example 86, the certificate revision list in the subject matter ofExample 82 can optionally comprise a version identifier.

Various embodiments may have different combinations of the operationalfeatures described above. For instance, all optional features of themethod described above may also be implemented with respect to anon-transitory, computer-readable storage medium. Specifics in theexamples may be used anywhere in one or more embodiments.

Examples 87-91 are a non-transitory, computer-readable storage mediumincluding instructions that, when executed by a computing system, causethe computing system to perform the operations of Examples 82-86.

Various embodiments may have different combinations of the operationalfeatures described above. For instance, all optional features of themethod described above may also be implemented with respect to anapparatus. Specifics in the examples may be used anywhere in one or moreembodiments.

Examples 92-96 are a system for revising rights of a device using acertificate revision list comprising means for executing the operationsof Examples 82-86.

In the above description, numerous details are set forth. It will beapparent, however, to one of ordinary skill in the art having thebenefit of this disclosure, that embodiments may be practiced withoutthese specific details. In some instances, well-known structures anddevices are shown in block diagram form, rather than in detail, in orderto avoid obscuring the description.

What is claimed is:
 1. A method comprising: receiving, by a mediasecurity controller circuit of a media storage device from a renderingdevice, a request to render a media item that is stored in a memory ofthe media storage device; sending to the rendering device, by the mediasecurity controller circuit in response to receiving the request, anauthorization file stored in memory of the media storage device, theauthorization file comprising first instructions to be executed by themedia security controller circuit and second instructions to be executedby the rendering device to render the media item; receiving, by themedia security controller circuit, at least a portion of theauthorization file from the rendering device, wherein the portion of theauthorization file comprises the first instructions; executing, by themedia security controller circuit, the first instructions to send to therendering device a message for the rendering device to obtain a portionof data from the memory of the media storage device and to provide theportion of the data to the media security controller circuit, whereinthe data in the memory of the media storage device relates to the mediaitem to be rendered by the rendering device; receiving from therendering device, by the media security controller circuit, the portionof the data obtained by the rendering device from the memory of themedia storage device; transforming, by the media security controllercircuit, the portion of the data obtained by the rendering device fromthe memory of the media storage device; and sending to the renderingdevice, by the media security controller circuit, the transformedportion of the data.
 2. The method of claim 1, wherein the transformedportion of the data comprises data for the rendering device to renderthe media item.
 3. The method of claim 1, wherein transforming theportion of the data comprises at least one of decrypting the portion ofthe data, encrypting the portion of the data, or compressing the portionof the data.
 4. The method of claim 1, wherein the media securitycontroller circuit comprises a second memory to store an authorizationkey corresponding to the transformed portion of the data, and whereintransforming the portion of the data comprises decrypting, by the mediasecurity controller circuit, the portion of the data using theauthorization key.
 5. The method of claim 1, further comprising:performing a first handshake between the media security controllercircuit and the rendering device based on public key infrastructurecryptography; performing a second handshake between the media storagedevice and the rendering device based on symmetric key cryptography; andestablishing a secure session with the rendering device based on thefirst handshake and the second handshake.
 6. The method of claim 1,wherein transforming the portion of the data comprises: receiving, bythe media security controller circuit, a set of instructions specifyingan authorization key for transforming the portion of the data, whereinthe set of instructions enable forensic analysis to identify the mediasecurity controller circuit to a third party; and creating, by the mediasecurity controller circuit, the transformed portion of the data usingthe authorization key, wherein the transformed portion of the dataidentifies the media security controller circuit to the third party. 7.The method of claim 1, further comprising: synchronizing a firstcertificate revision list of the media security controller circuit witha second certificate revision list of the rendering device, wherein thefirst certificate revision list and the second certificate revision listdescribe one or more changes to a set of rights.
 8. An apparatuscomprising: means for receiving, from a rendering device, a request torender a media item that is stored in a memory of a media storagedevice, wherein the means for receiving is integrated within the mediastorage device; means for sending to the rendering device, in responseto receiving the request, an authorization file stored in memory of themedia storage device, the authorization file comprising firstinstructions and second instructions to be executed by the renderingdevice to render the media item; means for receiving at least a portionof the authorization file from the rendering device, wherein the portionof the authorization file comprises the first instructions; means forexecuting the first instructions received in the portion of theauthorization file, the means for executing sends to the renderingdevice a message for the rendering device to obtain a portion of datafrom the memory of the media storage device and to provide the portionof the data to the media storage device, wherein the data in the memoryof the media storage device relates to the media item to be rendered bythe rendering device, wherein the data in the memory of the mediastorage device is stored according to a file system unknown to the meansfor executing; means for receiving from the rendering device the portionof the data obtained by the rendering device from the memory of themedia storage device; means for transforming the portion of the dataobtained by the rendering device from the memory of the media storagedevice; and means for sending to the rendering device the transformedportion of the data.
 9. The apparatus of claim 8, wherein thetransformed portion of the data comprises data for the rendering deviceto render the media item.
 10. The apparatus of claim 8, furthercomprising at least one of: means for decrypting the portion of thedata; means for encrypting the portion of the data, or means forcompressing the portion of the data.
 11. The apparatus of claim 8,further comprising means for decrypting the portion of the data using anauthorization key stored in a second memory, the authorization keycorresponding to the transformed portion of the data.
 12. The apparatusof claim 8, further comprising: means for performing a first handshakewith the rendering device based on public key infrastructurecryptography; means for performing a second handshake with the renderingdevice based on symmetric key cryptography; and means for establishing asecure session with the rendering device based on the first handshakeand the second handshake.
 13. The apparatus of claim 8, furthercomprising: means for receiving a set of instructions specifying anauthorization key for transforming the portion of the data, wherein theset of instructions enable forensic analysis to identify the apparatusto a third party; and means for creating the transformed portion of thedata using the authorization key, wherein the transformed portion of thedata identifies the apparatus to the third party.
 14. The apparatus ofclaim 8, further comprising: means for synchronizing a first certificaterevision list with a second certificate revision list at the renderingdevice, wherein the first certificate revision list and the secondcertificate revision list describe one or more changes to a set ofrights.
 15. An apparatus comprising: means for sending a request torender a media item that is stored in a memory of a media storagedevice; means for receiving an authorization file stored in the memoryof the media storage device, the authorization file comprising firstinstructions to be executed by a media security controller circuit ofthe media storage device and second instructions; means for receiving amessage from the media security controller circuit, the messageinstructing the apparatus to read a portion of data from the memory ofthe media storage device and to provide the portion of the data to themedia security controller circuit, wherein the data in the memory of themedia storage device relates to the media item to be rendered, whereinthe data in the memory of the media storage device is stored accordingto a file system unknown to the media security controller circuit; meansfor sending the portion of the data read from the memory of the mediastorage device to the media security controller circuit; and means forreceiving a transformed portion of the data from the media securitycontroller circuit; and means for rendering the transformed portion ofthe data.
 16. The apparatus of claim 15, further comprising: means forcreating a playback map based on the transformed portion of the datareceived from the media security controller circuit, wherein theplayback map comprises data to render the media item.
 17. The apparatusof claim 15, further comprising: means for processing the transformedportion of the data using a session key that is shared with the mediastorage device.
 18. The apparatus of claim 15, further comprising: meansfor performing a first handshake with the media storage device based onpublic key infrastructure cryptography; means for performing a secondhandshake with the media storage device based on symmetric keycryptography; and means for establishing a secure session with the mediasecurity controller based on the first handshake and the secondhandshake.
 19. The apparatus of claim 15, further comprising: means forsynchronizing a first certificate revision list with a secondcertificate revision list of the media security controller circuit,wherein the first certificate revision list and the second certificaterevision list describe one or more changes to a set of rights.
 20. Theapparatus of claim 15, wherein the transformed portion of the datacomprises data for the means for rendering to render the media item.